Caractérisation moléculaire et fonctionnelle de la jonction mobile contrôlant l'invasion de la cellule hôte par Toxoplasma gondii. Les apicomplexes sont des parasites eucaryotes responsables d'infections humaines et animales, dont le paludisme et la toxoplasmose. La plupart sont des parasites intracellulaires obligatoires ; l'entrée dans la cellule hôte est donc un évènement crucial dans leur cycle de développement. Ce processus, conservé au sein du phylum, implique la sécrétion séquentielle du contenu de deux organites : les micronèmes et les rhoptries. Lors de l'invasion, le parasite établit un contact étroit entre son extrêmité apicale et la membrane plasmique de la cellule hôte, appelé la jonction mobile (JM). La JM est un point d'ancrage à la cellule hôte qui est initié chez Toxoplasma par la sécrétion de protéines du col des rhoptries appelées TgRON2/RON4/RON5/RON8 (complexe de RONs). Ces protéines sont sécrétées dans la cellule hôte et TgRON2 est insérée dans la membrane de la cellule hôte. TgRON2 peut servir de récepteur à la protéine TgAMA1 (Apical Membrane Antigen 1) qui est une protéine de micronèmes sécrétée à la surface du parasite durant l'invasion. L'interaction AMA1-RON2 est également conservée chez Plasmodium, mais il n'existe pas de réactivité croisée entre espèces d'apicomplexes. La résolution de la structure de la protéine recombinante TgAMA1 en complexe avec un peptide TgRON2 nous a permis de déterminer des résidus critiques à l'interaction entre ces deux protéines in vitro et à l'invasion du parasite in vivo, et de définir les bases structurales de la spécificité intra-espèce de l'interaction AMA1-RON2. Par l'obtention d'une souche dépourvue de TgAMA1, nous montrons qu'AMA1 n'est pas essentielle à la survie du toxoplasme, comme il avait été supposé depuis longtemps. Nous confirmons le rôle clé de cette protéine dans l'invasion et la formation de la JM. Les mutants dépourvus d'AMA1 sont capables d'insérer le complexe de RONs dans la cellule hôte mais se détachent plus fréquemment, entrainant des invasions abortives. L'invasion résiduelle observée en absence d'AMA1 pourrait impliquer des protéines homologues à TgAMA1, TgRON2 et TgRON4, dont nous avons entamé la caractérisation moléculaire et fonctionnelle.Mot-clés : Apicomplexes, Toxoplasma gondii, invasion, jonction mobile, micronèmes, rhoptries / Molecular and functional characterisation of the moving junction controlling host cell invasion by Toxoplasma gondiiAbstract:Apicomplexa are eukaryotic parasites responsible for a variety of human and animal diseases, including malaria or toxoplasmosis. Most of them have an obligatory intracellular stage; thus, the invasive process is a crucial step in their developmental cycle. It implies the sequential secretion of two organelles: micronemes and rhoptries. During invasion, the parasite establishes a structure called the moving junction (MJ), which is a close apposition between the apical end and the plasma membrane of host cell. The MJ is an anchoring point for invasion that is initiated in Toxoplasma by the secretion of rhoptry neck proteins named TgRON2/RON4/RON5/RON8 (the RONs complex). These proteins are exported to the host cell cytoplasm and TgRON2 spans the host cell membrane. There, TgRON2 will function as a receptor to Apical Membrane antigen 1 (TgAMA1), which is a micronemal protein displayed on the surface of the parasite during the invasion process. The AMA1-RON2 interaction is conserved in Plasmodium but there is no interspecies cross-binding.We have determined the structure of a TgAMA1 recombinant protein in complex with a TgRON2 peptide, which allowed us to determine which residues are critical for the interaction between both proteins in vitro and for parasite invasion in vivo. Moreover, the co-structure explains at the structural level the evolutionary constraint of the AMA1-RON2 interaction. By generating an AMA1 null strain in T. gondii, we demonstrate that TgAMA1 is not an essential gene, as claimed before. We confirm the importance of AMA1 in invasion and its key role in MJ formation. AMA1 null parasites insert the RON complex into the host cell but are more frequently detached from it, causing abortive invasions. The residual invasion might involve proteins homologous to TgAMA1, TgRON2 and TgRON4, for which the molecular and functional characterization is undertaken.Keywords: Apicomplexes, Toxoplasma gondii, invasion, moving junction, micronemes, rhoptries

M.Sc. / Research into blood protozoans (haematozoans) infecting African tortoises is scanty with only a few records published, many during the early part of the last century. Little research had been done on the blood parasites of tortoises examined in this study namely, Kinixys lobatsiana, K. belliana belliana, K. natalensis, Geochelone pardalis pardalis, G. pardalis babcocki and Chersina angulata. The study therefore aimed to: 1) examine apicomplexan haematozoan parasites infecting several of South Africa’s indigenous tortoises and compare them with published species descriptions, especially from neighbouring Mozambique; 2) provide host details (identity, ectoparasites, host weight and gender, effects of blood parasites on host cells) and locality records in different seasons for described and new apicomplexan species; 3) describe new and recorded parasites using morphometrics and, if possible, ultrastructural characteristics 4) attempt apicomplexan DNA extraction, amplification and, if feasible, purification; and 5) establish a basis for future research as a result of the acquired knowledge. During the current study, 154 tortoises of six species in three genera, both captive and wild, and from four South African provinces (Gauteng, North West, Kwazulu-Natal and Western Cape) were sampled. Giemsa stained blood smears and use of image analysis enabled morphometric analysis of the apicomplexans and their effects on host cells, while some blood preserved in Karnovsky’s and Todd’s fixatives received detailed examination by transmission electron microscopy. Lastly, blood preserved in lysis buffer during collection, and with the highest parasitaemias, was subjected to parasite DNA extraction and amplification. Comparisons between a published account of apicomplexans recorded from K. b. belliana in Mozambique, and those found in the current study, identified two haemogregarine species. In the present research, Haemogregarina fitzsimonsi Dias, 1953 infected 2/27 (7%) wild North West K. lobatsiana, 2/3 (66%) captive Kwazulu-Natal K. natalensis, 7/14 (50%) captive Kwazulu- Natal K. b. belliana, 3/6 (50%) captive Kwazulu-Natal G. p. pardalis, 2/41 (5%) wild G. p. babcocki and 13/37 (35%) captive Gauteng G. pardalis. In addition, Haemogregarina parvula Dias, 1953, infected 2/14 (14%) captive K. b. belliana and 1/10 (10%) captive G. p. pardalis. An unknown species of haemogregarine, possibly also H. fitzsimonsi occurred in 6/16 (38%) Chersina angulata from the Western Cape. As well as haemogregarines, two haemoproteids were identified: Haemoproteus balazuci Dias, 1953 infected 2/27 (7%) wild North West K. lobatsiana, 2/2 (100%) captive Gauteng K. lobatsiana and 1/41 (2%) wild North West G. p. babcocki; Haemoproteus sp., a likely new species, was found in 1/3 (33%) captive K. natalensis. Infections with Haemogregarina and Haemoproteus were not concurrent in this study, but were found to occur concurrently in Dias (1953) findings, and only the two Haemogregarina spp. occurred together in captive Kwazulu-Natal G. p. pardalis tortoises, which do not occur naturally in the region. Haemogregarina fitzsimonsi did not appear region or host specific, since it infected 5/6 species of tortoises from all provinces sampled. Haemogregarina parvula apparently existed only in tortoises from Kwazulu-Natal. Furthermore, captive Gauteng female tortoises were found to have a higher rate of infection than males and heavier tortoises showed a lower intensity infection than lighter and younger tortoises. On average season appeared to have a slight affect on parasite prevalence, with a higher prevalence during the summer rather than the winter, possibly a result of the activity of the assumed vector, which may be the tick species Amblyomma marmoreum (found on G. pardalis) and/or Amblyomma hebraeum (found on C. angulata). For the new Haemoproteus sp., the small sample size meant that meaningful data on host-specificity and range was not gathered, but Hp. balazuci occurred in K. lobatsiana in the drier regions of the North West and Gauteng. Although DNA extraction was possible for H. fitzsimonsi, the technique requires further refinement and samples with greater parasitemias before it can be used with additional material, and sequencing can be attempted. Thus, new localities, hosts, host data and possible vectors (ticks) were recorded for the apicomplexan species identified by Dias (1953) and they were re-described using modern techniques. Also, possibly new Haemogregarina and Haemoproteus spp. were recorded, but their identity requires confirmation by DNA analysis. It is anticipated that these, and future results, will increase the knowledge of the ecology and biodiversity of apicomplexan haematozoans parasitising chelonian hosts in South Africa, with possible application to the conservation of these and other tortoise species around the world.

As doenças de veiculação hídrica são causadas, principalmente, por micro-organismos patogênicos de origem entérica. A partir da década de 1980, as enfermidades causadas por protozoários parasitas emergiram e reemergiram e se tornaram um problema de saúde pública com relevância na atualidade, especialmente para grupos populacionais mais vulneráveis, como pessoas que vivem com HIV/aids. Este trabalho teve por objetivo avaliar a prevalência de parasitas emergentes e reemergentes em crianças que vivem com HIV/aids atendidas no HCFMRP-USP e os condicionantes socioambientais envolvidos. Foram coletadas 47 amostras de fezes de 17 crianças de quatro a 13 anos que vivem com HIV/aids atendidas no HCFMRP- USP, no período de março a setembro de 2013. Do total, 52,9% das crianças eram do sexo feminino e 47,1% do sexo masculino, sendo que 52.9% eram pardas, 35,3% brancas e 11,8% negras. A análise de coccídeos intestinais oportunistas, como Cryptosporidium spp., Cyclospora spp. e Cystoisospora spp. foi realizada pelo método de Ziehl Nielsen Modificado, enquanto que para a pesquisa de cistos de Giardia spp. e outros parasitas foi utilizado o método de sedimentação espontânea por meio do Kit Coproplus®. As presenças dos parasitas Giardia spp e Cryptosporidium spp. foram confirmadas por meio de ensaios imunoenzimáticos para detecção de antígenos (métodos de Elisa). Foi ainda aplicado um questionário referente às questões socioambientais, hábitos comportamentais e hábitos de higiene pessoal e alimentar adotados pelas crianças participantes do estudo e algumas informações adicionais foram coletadas dos prontuários. Os resultados obtidos revelaram uma alta frequência de parasitas em crianças que vivem com HIV/aids atendidas no HCFMRP- USP (76,5%), sendo representados por agentes patogênicos: Giardia spp. (35,3%), Cryptosporidium spp. (23,5%), Cyclospora spp. (5,9%); e agente comensal: Entamoeba coli (47,1%). Apesar de se tratar de protozoários de veiculação hídrica, considera-se que a água utilizada pelas crianças não seja a principal via de transmissão desses parasitas, tendo em vista as evidencias que existem da boa qualidade da água que abastece a região, procedente do Aquífero Guarani. Dessa forma, considera-se que as características socioambientais, os hábitos de higiene pessoal e alimentar adotados pelas crianças bem como o contato com outras pessoas e/ou animais podem ter contribuído para o quadro de enteroparasitoses. A alta prevalência de parasitas encontrada no presente estudo nos remete a grandes preocupações em termos de saúde pública, uma vez que, o quadro clínico para Giardia spp., Cryptosporidium spp, Cyclospora spp. pode evoluir para uma morbidade grave quando há uma supressão do sistema imunológico do indivíduo. Dessa forma, conclui-se que alguns aspectos são imprescindíveis para uma melhoria da qualidade de vida das crianças que vivem com HIV/aids, dentre os que se destacam: o diagnóstico precoce para enteroparasitas, a implementação da análise coprológica de protozoários emergentes e reemergentes na rotina da atenção desses pacientes, o uso correto da terapia antirretroviral, bem como o monitoramento das características imunológicas / The waterborne diseases are caused mainly by pathogenic microorganisms enteric origin. From the 1980s, the diseases caused by protozoan parasites emerged and re-emerged and have become a public health problem of relevance today, especially for the most vulnerable population groups such as people living with HIV/aids. This study objetived to assess the prevalence of emerging and re-emerging parasites in children living with HIV/aids followed at HCFMRP-USP and socioenvironmental constraints involved. Were collected 47 stool samples from 17 children aged four to 13 years living with HIV/aids followed at HCFMRP- USP, in the period from March to September 2013. Of the total, 52.9% of children were female and 47.1% male, and that 52.9% were brown, 35.3% white and 11.8% black. The analysis of intestinal coccidia opportunistic as Cryptosporidium spp. Cyclospora spp. and Cystoisospora spp. was performed by the modified Ziehl Nielsen method, while for the research of Giardia spp. and other parasites was used by spontaneous sedimentation method by means of Kit Coproplus®. The presence of Giardia spp and Cryptosporidium spp. were confirmed by enzyme immunoassays for the detection of antigens (ELISA methods). Was still applied a questionnaire relating to socioenvironmental issues, behavioral habits and personal hygiene habits and food adopted by the children participating in the study and some additional information was collected from medical records of children. The results revealed a high frequency of parasites in children living with HIV/aids followed at HCFMRP-USP (76.5%), being represented by pathogens: Giardia spp. (35.3%), Cryptosporidium spp. (23.5%), Cyclospora spp. (5.9%), and commensal agent: Entamoeba coli (47.1%). Although it being waterborne protozoa, is considered that the water used by children is not the main route of transmission of these parasites, in view of the evidence that there are good-quality water that supplies the region, coming from the Guarani Aquifer. Thus, it is considered that the socioenvironmental characteristics, personal hygiene and food adopted by children as well as contact with other people and / or animals may have contributed to the enteroparasitosis frame. The high prevalence of parasites found in this study leads us to great concern in terms of public health, since the clinical picture for Giardia spp., Cryptosporidium spp. e Cyclospora spp. may progress to severe morbidity when there is a suppression of the immune system of the individual. Thus, it is concluded that some aspects are essential to improving the quality of life for children living with HIV/aids, among which stand out: early diagnosis for intestinal parasites, the implementation of coprologic analysis of emerging and reemerging protozoan in routine care of these patients, the correct use of antiretroviral therapy, as well as monitoring of the immunological characteristics

Thesis (M. Agricultural Management (Animal Production)) -- University of Limpopo, 2018 / Ethno veterinary medicine practices are popular among the resource constrained small-holder farmers. Nonetheless, the effectiveness of traditional remedies particularly the indigenous plants has not been extensively documented. Hence, this study was conducted to determine efficacy of indigenous plant extracts used by small-holder farmers in Chief Albert Luthuli Local Municipality, Mpumalanga Province, South Africa for internal parasites control. Information on indigenous plants used for the control of internal parasites of livestock by local farmers in the study area was gathered through a questionnaire survey. A total of 188 livestock farmers (both males and females) of mixed ages were interviewed. Thirteen different plants were frequently mentioned by the respondents as remedies for livestock internal parasites. Of these, seven plants could be identified up to their families and species. Plant species collected were Dicerocaryum sp (50%), Pappeacapensis (61%), Aloe ferox (90%), Helichrysum sp (56%), Senecio congestus (83%), Senecio barbertonicus (67%) and Gardenia sp (73%). These plants were extracted using distilled water and analysed to determine their efficacy through in vitro assays; Egg hatch, larval development and larval mortality assays. All the assays were performed at different concentrations of 2.5mg/ml, 5.0mg/ml and 7.5mg/ml. The nematode third stage larvae were incubated for 24hr, 48hr and 72hr during the larval mortality assay. The present study showed that all the seven-plant species under investigation possessed some anthelmintic activities of varying strength. The highest egg hatch inhibition was observed from the extracts of Senecio barbertonicus with 100 % and the lowest from Dicerocaryum eriocarpum with 2.25 %, for larval development the highest was Gardenia sp 100 % and the lowest Helichrysum sp 26 % at concentration 7.5 mg/mL respectively. Whereas, the highest in larval mortality assay was Senecio barbertonicus and Gardenia sp achieved 100 % after 48hrs and the lowest was Dicerocaryum eriocarpum with49.89 % after 72hrs at concentration 7.5 mg/mL respectively. The use of other different forms of extraction media is recommended because different results can observe and be compared with the results of the present study. Toxicity studies on the indigenous plants observed to have stronger anthelmintic activities would assist in the future recommendation of these remedies for large scale or commercial use as anthelmintic drugs. Keywords: ethno veterinary medicine, gastrointestinal parasites, anthelmintic

Les sacs rénaux des céphalopodes sont communément le siège d’infections parasitaires spectaculaires provoquées principalement par des ciliés apostomes du genre Chromidina et des mésozoaires, les dicyémides. Les formes végétatives sont vermiformes et peuvent atteindre plusieurs mm de long. Elles sont fixées par leur partie antérieure aux cellules rénales. La diversité de ces parasites énigmatiques, basée sur des morpho-espèces, reste très mal connue pour les chromidinés et aucune donnée moléculaire n’est disponible pour ces ciliés. Les Dicyémides ont été en revanche plus étudiés mais les données morphologiques et moléculaires sont parcellaires et leurs relations phylogénétiques restent débattues. Au cours de cette thèse, nous nous sommes proposés d’étudier ces deux groupes afin d’évaluer leur biodiversité chez les céphalopodes méditerranéens et d’Atlantique, et de fournir plus d’éléments pour la compréhension de leur systématique et de leur phylogénie. Ainsi, à partir d’un large échantillonnage de céphalopodes d’Atlantique (Concarneau, France) et méditerranéens (La Goulette, Tunisie) prélevés sur 3 années consécutives, nous avons entrepris de caractériser morphologiquement et génétiquement ces parasites en réalisant une analyse moléculaire du marqueur ADNr 18S afin d’aborder la notion d’espèce, de préciser leur spécificité d’hôte, de corréler la diversité morphologique et génétique, et de mesurer la variabilité génétique au sein d’une même morpho-espèce.Dans nos échantillonnages, la prévalence de l’infection par des chromidinés s’est révélée faible, certainement biaisée par les milieux échantillonnés, essentiellement benthiques, alors que les chromidinés infectent préférentiellement les céphalopodes pélagiques. Nous pouvons cependant prédire que leur biodiversité est sous-estimée, car deux nouvelles espèces ont pu néanmoins être décrites. Nous avons pu obtenir pour la première fois des séquences de l’ADNr 18S de ces parasites. Les analyses phylogénétiques robustes montrent que les chromidinés se positionnent parmi les ciliés apostomes au sein de la classe des Oligohymenophorea.La prévalence des dicyémides était beaucoup plus importante (88%). Un problème important dans la systématique des dicyémides est que bon nombre de morpho-espèces nommées sont basées sur des descriptions morphologiques incomplètes qui entrainent des ambiguïtés dans leur détermination. Ceci nous a amenés à redécrire de façon détaillée sur tous les stades de développement l’espèce Dicyemennea eledones rencontrée dans nos échantillonnages. Les analyses phylogénétiques des séquences du marqueur ADNr 18S obtenues au cours de cette étude et intégrant les séquences de dicyémides déjà connues, nous ont permis de définir 10 clades robustes. Les morpho-espèces ne se distribuent pas de façon non ambigüe au sein de ces clades puisque certaines morpho-espèces se retrouvent dans plusieurs clades et que certains clades peuvent regrouper plusieurs morpho-espèces. Ceci pose la question de la pertinence de ce marqueur ADNr 18S pour l’identification des espèces, voire même des genres, et pose également la question de la pertinence des marqueurs morphologiques utilisés à ce jour pour la systématique des dicyémides. / The renal sacs of cephalopods are an uncommon habitat for two phylogenetically distant parasites, dicyemid mesozoa and ciliate chromidinids. These are wormlike organisms, which can reach a few millimetres in length and are attached to the renal epithelia by their anterior part. Information was mainly based on morphological criteria and little is known about the biodiversity and taxonomy of these enigmatic parasites. Concerning the chromidinids, only 4 morpho-species have been described and there are no molecular data available. Dicyemids have been a little more studied, but morphological criteria are still incomplete for some species and not all life stages have been studied. The molecular data are sparse and the phylogenetic position of these organisms is uncertain.During this thesis, we have undertaken to study these two groups with regard to their biodiversity in cephalods from the Mediterranean Sea and the Atlantic Ocean. The aims are to obtain more elements for the comprehension of their systematics and phylogeny. Starting from a large sample of cephalopods from the Atlantic Ocean (Concarneau, France) and the Mediterranean Sea (La Goulette, Tunisia), fished during 3 consecutive years, we characterized the parasites from a morphological and molecular point of view. We realised a molecular analysis of the 18S rDNA marker in order to look at the notion of species, to precise their host specificity, to correlate the morphological and genetic diversity and to measure the genetic variability within one morpho-species.In our samples, the prevalence of the infection by chromidinids was revealed to be weak, probably biased by the position of the collection in the water column. The sampled hosts were predominantly benthic, while chromidinids mainly infect pelagic cephalopods. We predict that the diversity is underestimated, even if we were able to describe two new species. We obtained for the first time molecular data from the 18S rDNA marker. The robust phylogenetic analyses show that chromidinids are positioned within the apostome ciliates, belonging to the Oligohymenophorea.In our samples, the prevalence of the infection by dicyemids was shown to be more important (88%). A major problem in the dicyemid systematics is that a large number of named morpho-species are based on incomplete morphological descriptions, entailing ambiguities in their identification. We therefore redescribed all stages of the development of the species Dicyemennea eledones of our samples in detail. Phylogenetic analyses of the 18S rDNA marker sequences of our samples, combined with the sequences available in databases, allowed us to define 10 robust clades. The morpho-species are not distributed in a non ambiguous manner within these clades, as some can be found in different clades and some clades can regroup more than one morpho-species. This leads to the question of the relevance of the 18S rDNA marker for the identification of species and even genera. It also challenges the relevance of morphological criteria currently used for the dicyemid systematics.

Metazoan parasites threaten the development and expansion of yellowtail kingfish (Seriola lalandi) sea-cage aquaculture in Australia. There is international speculation that parasite transmission from farmed to wild fish leads to increased incidence of parasitism in wild fish. Conversely, transfer of parasites from wild fish to farmed fish can negatively impact upon the health of farmed fish. Baseline information on the parasite assemblage of wild S. lalandi in Australia will: 1) allow informed judgments to be made in order to responsibly monitor, and perhaps remedy, potentially negative impacts and; 2) enable identification of parasite species of potential harm to the Australian S. lalandi aquaculture industry. I collected wild Seriola spp. (Carangidae) throughout southern Australia and examined them for metazoan parasites. Fifty-six metazoan parasite species are identified, including one new species. A taxonomic listing is provided for the metazoan parasites found. Taxonomic descriptions are made for the blood fluke Paradeontacylix godfreyi n. sp. (Digenea: Sanguinicolidae) and a redescription is provided for the parasitic copepod Naricolax chrysophryenus (Cyclopoida: Bomolochidae). A qualitative risk assessment was devised for the metazoan parasite taxa identified for the sea-cage aquaculture of S. lalandi in South Australia. Risk was interpreted considering the likelihood and consequence of parasite establishment and proliferation. The monogeneans Benedenia seriolae and Zeuxapta seriolae were considered extremely likely to establish and proliferate. Benedenia seriolae also poses high potential negative consequences for cost-effective S. lalandi sea-cage farming. However, the absence of potential mitigation methods and parasite management for Paradeontacylix spp. (Digenea), Kudoa sp. and Unicapsula seriolae (Myxozoa) indicates that these species may also present high negative consequences for S. lalandi aquaculture in Australia. The nature of wild Seriola migrations is critical for an understanding of the potential impact of disease and parasite interactions between wild and farmed fish. A small-scale tagging programme of wild-caught S. lalandi and S. hippos in South Australia provided insight into the movements of these species. Recapture results indicate that large S. lalandi remain in, or return to, northern Spencer Gulf. S. lalandi also move past sea-cage farms in Fitzgerald Bay, northern Spencer Gulf, which is an important consideration in view of potential expansion of the S. lalandi sea-cage industry in Spencer Gulf. There is surprisingly little experimental assessment on parasite transmission from farmed fish to wild fish. Studies assessing parasite interactions between wild and cultured fish employ models to quantify parasite population levels of cultured, wild and escaped fish, while others carry out comparative surveys of parasite prevalence and intensity over time, in areas close to and distant from farming activity. I provide preliminary data on ectoparasite prevalence and intensity on wild S. lalandi in areas close to, distant from and where there is no sea-cage farming in southern Australia. I review methods employed in the northern hemisphere to assess sea-louse transfer between wild and farmed salmon and propose methods for assessing monogenean parasite transmission from farmed to wild S. lalandi in Australia. In summary, this thesis provides insight into the potential for parasite interactions between wild and farmed S. lalandi. I document the parasite assemblage of wild and farmed S. lalandi and wild S. hippos and provide baseline data on ‘natural’ parasite prevalence and intensity. I provide a taxonomic description of a new species of blood fluke. I indicate the likelihood of parasite transfer from wild fish to farmed S. lalandi, and identify parasite taxa with potentially negative consequences for sea-cage aquaculture. I provide the first firm data that wild S. lalandi move past one area where kingfish are farmed in sea-cages in South Australia. Finally, I propose procedures to better understand the potential for monogenean parasite transmission from farmed S. lalandi to wild fish. This thesis reports new information that is important when considering and managing expansion of the S. lalandi sea-cage aquaculture industry throughout Australia. It also provides baseline data on natural parasite levels to enable ongoing monitoring of the potential impacts of the industry on wild fish populations. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1294807 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007

Bibliography: leaves 111-137.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.